CAJ | 학술논문

为了探讨高密度CO2（dense phase carbon dioxide，DPCD）对水产品腐败菌的杀菌效果和机制，以一株凡纳滨对虾优势腐败菌（Chryseobacterium sp. LV1）为研究对象，研究了DPCD处理温度（30～55℃）、压力（5～25 MPa）、时间（5～60 min）对杀菌效果的影响，分析了DPCD处理前后该菌理化性质的变化。结果表明：DPCD对其具有较好的杀菌效果，温度升高、压力增大、延长时间都会增强杀菌效果，而且超临界CO2比亚临界CO2的杀菌效果好。当在45℃、15 MPa和55℃、15 MPa下处理菌悬液30 min时，菌落总数均能下降5个对数；菌悬液的pH值从6.97分别下降至5.58和5.56；细胞外蛋白由最初的78.69μg/mL分别增至151.91和157.40μg/mL，200～800 nm范围内的吸光度值增大，这说明DPCD处理改变了其细胞膜的通透性，造成胞内蛋白质和核酸泄漏；可溶性和不溶性蛋白的电泳图谱发生变化，说明DPCD处理能够诱导Chryseobacterium sp. LV1可溶性蛋白质变性，降低其溶解度；能够钝化与其新陈代谢相关的14种酶类；但不会造成其DNA的降解。因此，DPCD处理致使其理化性质的改变可能是杀菌的主要原因之一。研究结果将为DPCD技术在对虾加工中的应用提供参考。
위료탐토고밀도CO2（dense phase carbon dioxide，DPCD）대수산품부패균적살균효과화궤제，이일주범납빈대하우세부패균（Chryseobacterium sp. LV1）위연구대상，연구료DPCD처리온도（30～55℃）、압력（5～25 MPa）、시간（5～60 min）대살균효과적영향，분석료DPCD처리전후해균이화성질적변화。결과표명：DPCD대기구유교호적살균효과，온도승고、압력증대、연장시간도회증강살균효과，이차초림계CO2비아림계CO2적살균효과호。당재45℃、15 MPa화55℃、15 MPa하처리균현액30 min시，균락총수균능하강5개대수；균현액적pH치종6.97분별하강지5.58화5.56；세포외단백유최초적78.69μg/mL분별증지151.91화157.40μg/mL，200～800 nm범위내적흡광도치증대，저설명DPCD처리개변료기세포막적통투성，조성포내단백질화핵산설루；가용성화불용성단백적전영도보발생변화，설명DPCD처리능구유도Chryseobacterium sp. LV1가용성단백질변성，강저기용해도；능구둔화여기신진대사상관적14충매류；단불회조성기DNA적강해。인차，DPCD처리치사기이화성질적개변가능시살균적주요원인지일。연구결과장위DPCD기술재대하가공중적응용제공삼고。
Dense phase carbon dioxide (DPCD) is a non-thermal pasteurization method that affects microorganisms and enzymes through molecular effects of CO2 under pressures below 50MPa and temperature below 60℃. The DPCD sterilization technique could be one of the most promising techniques for sterilizing foods without exposing them to adverse effects of heat, thereby retaining their fresh physical, nutritional, and sensory qualities. In order to investigate the sterilization effect and mechanism of aquatic product spoilage bacteria induced by dense phase carbon dioxide (DPCD), using a strain of Litopenaeus vannamei dominant spoilage bacteria (Chryseobacterium sp. LV1) as the research object, the effects of temperature (30-55℃), pressure (5-25 MPa), time (5-60 min) on sterilization were studied and the changes of Chryseobacterium sp. LV1 physicochemical properties were analyzed before and after DPCD treatment. The results showed that DPCD had a good bactericidal effect on Chryseobacterium sp. LV1. The sterilization effect is enhanced with increasing temperature, pressure and time, and the sterilization effect of supercritical CO2 was better than that of subcritical CO2. Under DPCD conditions of 45℃/15 MPa /30 min or 55℃/15 MPa /30 min, the total bacterial count decreased by 5 logs;the pH value of the bacterial suspension decreased from 6.97 to 5.58 and 5.56;the content of extracellular protein increased from the initial 78.69 to 151.91 and 157.40μg/mL;and the absorbance value from 200 to 800 nm increased. These results indicated that DPCD could result in intracellular protein and nucleic acid leakage of Chryseobacterium sp. LV1 because of permeability changes in its cell membrane. The SDS-PAGE electrophoretogram of Chryseobacterium sp. LV1 proteins showed that DPCD could reduce the solubility of Chryseobacterium sp. LV1 soluble protein because of soluble protein denaturation. The results detected by the API ZYM system kit showed that DPCD could inactivate 14 enzymes related to the metabolism of Chryseobacterium sp. LV1. The agarose gel electrophoretogram of Chryseobacterium sp. LV1 DNA showed that DPCD could not degrade the DNA of Chryseobacterium sp. LV1. Therefore, changes in the physicochemical properties of Chryseobacterium sp. LV1 induced by DPCD may be one of the main mechanisms of DPCD sterilization. The research results will provide a reference for the application of DPCD in the processing of shrimp.